Am Freitag, 10. April 2015, 14:22:08 schrieb mancha security:Hi mancha,>__asm__ __volatile__("": :"r"(p) :"memory")gcc -O2/3: mov presentclang -O2/3: mov present==> approach would be good too.Note, the assembly code does not seem to change whether to use this approach or the one I initially tested.CiaoStephan